ppa ocxo under the hood

[nige2000]

[rickmcinnis]

Is that one of ppa's or one you have made for yourself?

Looks really complicated.

Is that a power supply under the clock?

(for those, like me, who have no idea ...)

[Sligolad]

Its a PPA OCXO alright Rick, one of my casualties along the way!!
5v in so looks like some regulators to bring the voltage down a bit in there to my untrained eyes.

Certainly is a lot more in there than I thought, have you been able to get a name or brand of the clock capsule Nige?
Just interested in its provenance more than anything else.

[nige2000]

my knowledge of ocxo is almost zero
i didnt probe it much yet as i spent quite a while trying to get the hood off without breaking it although more than once came close to throwing it pretty far
i assume the clocks and the oven is in the little tin dome thing and it does get hot like a 4 second hot
looks like its frequency is derived from a 10mhz clk

i dont see any interesting markings on any of the parts
i know its a bit rich coming from me but it looks a bit home brew

[rickmcinnis]

One wonders just how "trick" it is to put a clock and a heating element in a metal case? Regulating the temperature isn't that difficult these days.

Couldn't be that big of a deal.

What's wrong with home-brew anyway?

Nothing in my experience

[sima66]

There are a couple of things that confuses me!
Not to long ago I remember JKeny saying something that the 5v lines are the worst (at list how I understood) and yet PPA still using only 5v for his clocks!
Another thing is why the PPA TCXO clock combo is so complicated in comparation to just another similar clock?!

EDIT: sorry for misleading!
There are a lot of things that confuses me, but this time I just mentioned two!

[nige2000]

There are a couple of things that confuses me!
Not to long ago I remember JKeny saying something that the 5v lines are the worst (at list how I understood) and yet PPA still using only 5v for his clocks!
Another thing is why the PPA TCXO clock combo is so complicated in comparation to just another similar clock?!

EDIT: sorry for misleading!
There are a lot of things that confuses me, but this time I just mentioned two!

probably quoting out of context its nothing to do with 5v the voltage
any pc voltage is dirty no matter how clean the power goes into the motherboard (all been relative of course)

pp sells his wares for profit and for maximum market saturation devices have to be compatible with all potential clients gear
it is easier to take the onboard +5v at the usb header as voltage supply for mobo clks its a quick fix
the usb header 5v is compromised with noise so an external supply is best

those that have run clks from a lifepo4 cell will get it difficult to revert to anything else
3.3v is nominal lifepo4 cell voltage

it a while since i had a ppa tcxo apart but i think there was a 3.3v regulation in it, when u have a ps as good as lifepo4 this regulation now has a negative effect rather than a positive for moderate to poor ps

that said i think the ppa tcxo works and had a benefit running of 3.3v cell

after the ppa tcxo it goes into a hex inverter which i suppose buffers the signal then goes into a transformer which isolates the signal but it also changes the waveform from a nice square wave to a sine wave and then into a capacitor which must be dc decoupling(or isolating the isolated) i think all this is not only unnecessary but harmful to the resolution of the sound the best sound i got out of a ppa tcxo is by bypassing all this

these tcxo or even ocxos afaik dont have any measurements or been certified but to me they sound as good as any and the ocxo marginally better than all ive tried (once bypassed)

moral of the story is that
id rather have a good clock with an exceptional power supply than an exceptional clk with a good ps
PS is the biggest challenge

http://www.ti.com/ww/mx/multimedia/webc ... 6-2010.pdf

[sima66]

There are a couple of things that confuses me!
Not to long ago I remember JKeny saying something that the 5v lines are the worst (at list how I understood) and yet PPA still using only 5v for his clocks!
Another thing is why the PPA TCXO clock combo is so complicated in comparation to just another similar clock?!

EDIT: sorry for misleading!
There are a lot of things that confuses me, but this time I just mentioned two!

probably quoting out of context its nothing to do with 5v the voltage
any pc voltage is dirty no matter how clean the power goes into the motherboard (all been relative of course)

pp sells his wares for profit and for maximum market saturation devices have to be compatible with all potential clients gear
it is easier to take the onboard +5v at the usb header as voltage supply for mobo clks its a quick fix
the usb header 5v is compromised with noise so an external supply is best

those that have run clks from a lifepo4 cell will get it difficult to revert to anything else
3.3v is nominal lifepo4 cell voltage

it a while since i had a ppa tcxo apart but i think there was a 3.3v regulation in it, when u have a ps as good as lifepo4 this regulation now has a negative effect rather than a positive for moderate to poor ps

that said i think the ppa tcxo works and had a benefit running of 3.3v cell

after the ppa tcxo it goes into a hex inverter which i suppose buffers the signal then goes into a transformer which isolates the signal but it also changes the waveform from a nice square wave to a sine wave and then into a capacitor which must be dc decoupling(or isolating the isolated) i think all this is not only unnecessary but harmful to the resolution of the sound the best sound i got out of a ppa tcxo is by bypassing all this

these tcxo or even ocxos afaik dont have any measurements or been certified but to me they sound as good as any and the ocxo marginally better than all ive tried (once bypassed)

moral of the story is that
id rather have a good clock with an exceptional power supply than an exceptional clk with a good ps
PS is the biggest challenge

http://www.ti.com/ww/mx/multimedia/webc ... 6-2010.pdf

Maybe the PPA TCXO can be moded to 3.3v, but I asked directly PPA can I power with 3.3v and his answer was ONLY 5V.

[nige2000]

If you get my clock working that should beJust try and see without modding anything
nothing will break
It will either work good bad or not at all
The one I tryed worked fine

If you get my clk working it will be best

[Crom]

my knowledge of ocxo is almost zero
i didnt probe it much yet as i spent quite a while trying to get the hood off without breaking it although more than once came close to throwing it pretty far
i assume the clocks and the oven is in the little tin dome thing and it does get hot like a 4 second hot
looks like its frequency is derived from a 10mhz clk

i dont see any interesting markings on any of the parts
i know its a bit rich coming from me but it looks a bit home brew

Very interesting that the frequency is derived from 10mhz - that would definitely be the cheapest way to do it. Take a look on ebay, there are loads of 2nd hand 10mhz OCXO's for sale. Could work out cheap to experiment and removing the lid might allow us to have dual power supply - one to the heater and the other for the crystal??

PS - I agree with your other comments about PP's homebrew silver transformer and other wave shaping mods. I played with that a lot and best result was without. It's like sticking a few valves in the way of the music.